Technical display model

ABSTRACT

The invention pertains to an architectural technical display model for the purpose of demonstrating architectural and HVAC mechanical systems which will maximize the effectiveness of an air curtain entrance way. The display model disassembles into convenient modules including a portable power unit to facilitate transportation and incorporates a number of novel constructional features which enhance the demonstrative effectiveness of such architectural display models.

United States Patent Inventor William L. Ellis 2876 Pease Drive. RockyRiver, Ohio 44116 Appl. No. 873,965

Filed Nov. 4, 1969 Patented July 27,1971

TECHNICAL DISPLAY MODEL 26 Claims, 10 Drawing Figs.

Int. Cl 00% 25/04 Field of Search 35/13, 16,

[56] References Cited UNITED STATES PATENTS 2,228,371 l/I94l Shaw 35/13Primary Examiner-Harland S. Skogquist Attorney-Farley. Forster andFarley ABSTRACT: The invention pertains to an architectural technicaldisplay model for the purpose of demonstrating architectural and HVACmechanical systems which will maximize the effectiveness of an aircurtain entrance way. The display model disassembles into convenientmodules including a portable power unit to facilitate transportation andincorporates a number of novel constructional features which enhance thedemonstrative effectiveness of such architectural display models.

PATENTEDJULZYIQYI 3.594.922

' SHEET 3 OF 4 Q INVENTOR ATTORNEYS TECHNICAL DISPLAY MODEL BACKGROUNDOF THE INVENTION The air curtain entranceway has become very popular forcommercial structures such as banks and supermarkets for which they arearchitecturally pleasing and inviting. However, problems have arisenwith both exterior wind currents from weather conditions and alsointerior air currents due to improper HVAC (heating, ventilating and airconditioning) systems resulting in relative ineffectiveness of the aircurtain. Through experience it has been learned that a commercialbuilding must be properly designed and constructed to accommodate aneffective air curtain entranceway. Otherwise large losses may result inthe HVAC system for the building and the environmental conditions insidethe building may be sufficiently abnormal to affect the performance ofemployees and comfort of customers. The present architectural technicaldisplay model has been developed to demonstrate the proper conditionsand requirements for use of an air door in a structure such as asupermarket. Such display models are principally constructed ofPlexiglass which incorporate all the significant architectural featuresin one unit mounted on a table top with folding legs which serves as acarrying case. The table tops are about 4 feet by 6 feet and the displaymodel essentially covers the entire top with a folded depth ofapproximately 1 foot. The motors and controls to demonstrate the HVACsystem have been made as a detachable unit to facilitate portability andtransportation since the resulting structures fully assembled areextremely heavy'to handle and carry.

Certain mechanical features of the display models such as various doorsinside the models are remote controlled. Nylon string and return springarrangements have been used but it has been found preferable to devisemore positive controls. It has also been found highly desirable toprovide for an external wind from a variable direction against the aircurtain entranceway to simulate actual weather conditions with differentwind velocities and directions.

SUMMARY OF THE INVENTION The invention utilizes a model principally madeof Plexiglass of a supermarket equipped with an air curtain entrancewayand mounted on a table top approximately 4 feet by 6 feet with foldinglegs. However, the fan motors for the HVAC system and also the aircurtain are located in a removable module that also includes the variousrheostats and switch controls for the entire display model. Specialsealsare provided between the module and the display model so that whenthe module is in place, there is no leakage in the duct work. Anexternal fan is provided on a hinged mounting at the air curtainentranceway to provide a wind flow controllable in both speed anddirection at the entrance to the display model. This external fan iscontrolled by one of the rheostats on the removable HVAC module. Anotherfan may be handheld at any position so as to direct the wind at thedisplay model from any direction at any speed desired within thecapability ofthc equipment. This second fan is to demonstrate the effectof wind velocity and direction upon the external roof-mounted air supplyto the HVAC system for the display model.

The technical display model incorporates a plurality of small windindicators located at various locations within the display model such asin front of the freezer chests or in front of the checkout counters.Other wind indicators are located within the duct work and near variousdoorways within the model. The doors themselves are operated by remotecontrol linkages including either a rack and pinion configuration orlever arm configuration. The control buttons for the doors are allgrouped together along one side of the table top near the controls forthe HVAC module. In summary then, the heavy components of the technicaldisplay model such as the two external fans and the HVAC module with thecontrols are all easily removable from the model facilitating singleperson transport from location to location.

DESCRIPTION OF THE DRAWINGS FIG. I is an overall perspective of thetechnical display model;

FIG. 2 is a perspective detail of one comer ofthe model of FIG. 1 withthe HVAC module removed, taken along the line 2, and showing the ductingleading from the module area;

FIG. 3 is an enlarged fragmentary detail sectional elevation taken alongthe line 3-3 of FIG. 1;

FIG. 4 is an enlarged fragmentary detail sectional elevation ofthemodule taken along the line 4-4 of FIG. 1;

FIG. 5 is an elevation taken along the line 5 of FIG. 4 showing thevarious controls on the module.

FIG. 6 is a detail enlarged perspective view ofa typical wind indicator;

FIG. 7 is an enlarged fragmentary perspective detail of the door-controlbuttons taken from the direction of the arrow 7 in FIG. 1;

FIG. 8 is a fragmentary plan view ofa typical lever arm door actuator;

FIG. 9 is a side elevation of the door actuator depicted in FIG. 8 andtaken along the line 9-9 of FIG. 8;

FIG. I0 is a fragmentary plan view of an alternate rack and pinionactuated door opener which also may be used in the technical displaymodel.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 the display model 20is permanently fastened to a table top 22. The table top 22 has foldinglegs and a handle not shown but provided in a conventional manner sothat the display model may be conveniently carried. The display model 20is constructed principally of Plexiglass so that the interior featuresmay be clearly seen. This is necessary because the display model must beas tightly sealed as an actual building since an operating HVAC systemis demonstrated. This particular display model represents a supermarket.However, the concepts embodied in the display model are equallyapplicable to other kinds of buildings. Inside the display model 20 arelocated such conventional itemsas freezer chests 24 and checkoutcounters 26. The floor plan of the model is typical for a supermarketwith a dividing wall 28 located between the shopping area and thestorage and receiving area 30. Exterior double doors 32 are provided forthe storage and receiving area and interior double doors 34 are providedin the dividing wall 28. An opening 29 that may be closed by remotecontrol is provided in the dividing wall 28 near the roof to simulate adefective architectural feature when it is open.

An air curtain main entranceway 36 is provided since the purpose of thisdisplay model is to demonstrate the proper HVAC and architecturalfeatures necessary to maximize the usefulness of an air curtainentranceway. Wind indicators 38 are placed throughout the display modelto indicate air current direction in important locations. Alternate andundesirable roof ventilators 40 such as might be found on typicalsupermarkets are also provided to help demonstrate HVAC systems. Ducting42 is provided in the ceiling of the display model over the shoppingarea as in a typical supermarket. The ducting 42 leads from ducting 44in the storage and receiving area 30. The ducting 44 in turn isconnected to the HVAC module 46 in the corner of the display model. TheHVAC module 46 contains all the motor-driven HVAC equipment and controlsfor the display model and as will be described later is removable fromthe display model so as to make the display model as light as possiblefor carrying purposes. An external air inlet and damper box 48 isprovided on top of the HVAC module. The HVAC module 46 also supplies airthrough ducts 48 and 50 to the air curtain entranceway 36. In order todemonstrate the effect of external wind upon the operation of the HVACsystem in the display model, external fans 52 and 54 are provided. Thehandheld fan 54 may be held at any position about the display model andplugged in to a rheostat located in the HVAC module 46 so that thesimulated wind velocity may be changed. The other fan 52 is mounted onhinged and removable brackets 56 and 58. The fan 52 may also becontrolled by a rheostat located in the HVAC module 46 so that variouswind velocities directed at the air curtain entranceway 36 may besimulated. The hinge 60 is provided with a knurled screw 62 in order toaim and retain the wind direction at the entranceway 36. The bracket 58is retained in a T-slot 64 with a second knurled screw 66. Thus the fan52 may be easily disassembled from the table top 22.

In FIG. 2 a detail of the corner of the display model and table 22 isshown with the HVAC module 46 removed. The air supplying duct 44 leadsfrom an upwardly opening fitting designated B-1. The upwardly openingfitting B-2 for the return air from the shopping area is mounted on thedividing wall 28 and is open through the dividing wall as shown inFIG. 1. A second opening C in the dividing wall 28 is for the buildingexhaust air. Upwardly opening pipes designated A connect with the ducts48 and 50 in FIG. 1 for the air curtain entranceway. The bottom of theHVAC module fits into the socket 68 in the top of the table 22. Each ofthe upwardly opening fittings B-1 and B-2 and pipes A are provided withsilicone gaskets to seal the air supply ductwork when the HVAC module isin place. The weight of the module helps to insure that proper sealingoccurs and this is the primary reason for the upwardly opening fittingsand pipes.

In FIGS. 3 and 4 the module is shown cut away and in place with respectto the display model. The HVAC module consists of a plenum chamber 70containing the mechanical systems. On top of the module is the outsideair supply and damper unit 48. The outside air supply enters through anelbow 72 which may swivel 360 at 74. Inside the unit are two dampers 76and 78 which provide for the proportioning of outside makeup air withreturn air. The return air enters at fitting B-2 and passes upwardthrough the duct 80 into the unit 48. The dampers 76 and 78 are set withknobs 82 on the outside ofthe unit 48. The mixed air passes downwardlythrough duct 84 and through building supply air fan 86. The buildingsupply air then passes from the fan 86 through the duct 88, fitting B-1and into duct 44. Silicone gaskets are located at joints 90 for fittingB-1 and 92 for fitting B-2. The air curtain entranceway is supplied byfan 94. Return air from duct 50 enters through duct 96 and leaves thefan 94 through duct 98. From duct 98 the air passes through duct 48 tothe air curtain entranceway. Ducts 96 and 98 fit over the upwardlystanding pipes designated A. The exhaust fan 100 is connected directlyto the opening C in the wall 28. The exit from the exhaust fan 102 isdirectly into the plenum chamber 70 of the HVAC module. Rheostats 104are also located within the plenum chamber 70 and operated by knobs 108on the outside of the HVAC module. The exhaust air from the exhaust fan100 circulates within the plenum chamber 70 and cools the rheostats I04and fans 86, 94 and 100. Switches f106 are located on the HVAC modulefor turning the fans on and off. A socket 110 is provided for either ofthe external fans described above and shown in FIG. 1. Also shown inFIG. 1 is a second socket 111 for the other fan. Socket 110 is rheostatcontrolled whereas socket 111 is not.

In summary thenthe module is a self-contained powerpack providing forall air circulation and pressure controls for the mechanical systems inthe display model. The module simply lifts on and offthe table top 22and upon reinstallation seals itself tightly to the fittings B-1 and B-2as well as the pipes A. The pipes A also have silicone sealing gasketsat location 112 shown in FIG. 4. Slots 114 and 116 shown in outline formare provided in the sidewalls of the HVAC module to allow the module tobe set into place over the fitting B-1 and B-2. Sihce the sidewallsdirectly face the dividing wall 28 and separating wall 118 there islittle leakage from within the plenum chamber 70. The wall 118 separatesthe module area from the service and storage area 30 of the displaymodel. The exhaust air within the plenum chamber 70 passes out from theplenum chamber to holes 120 in the bottom 122 of the HVAC module. Theholes 120 face the holes 124 shown in FIG. 2 from which the exhaust airpasses outside.

In FIG. 6 a typical wind indicator is shown. The wind indicator is adelicately balanced weather vane constructed of materials that allow thedirection of the air currents to be shown at the very lowest airvelocities possible. The U-shaped frame is constructed of nylon withholes drilled at 132 and 134 to provide integral nylon bushings for thepin 136. The blade 138 is made of a very light foam plastic material.The wind indicator will accurately indicate air direction and airmovement at velocities as low as 4 feet per minute. The frame 130 ofeach wind indicator is usually glued in place to the display model.

In FIG. 7, the corner of the display mode] at the doors 32 from theservice and storage area is shown. Knobs 140 are shown located in thetable top 22. These knobs connect through linkages shown in FIGS. 8, 9and 10 for controlling the various doors in the display model. Theparticular display model shown in FIG. 1 has remote control doors at 32,34 and just behind the air curtain entrance 36. The doors just behindthe air curtain entrance 36 are similar to the double doors at 34 and 32and therefore not shown.

In FIG. 8, the knob 140 is connected to a push-pull resilient wire 142which passes inside a tube 144 for the greater part of the length of thewire 142. The wire 142 is attached at 146 to a bellcrank 148. Thebellcrank 148 is attached at its fulcrum to the door hinge 150 of one ofthe double doors shown in outline form 152. A link 154 is attached tothe bellcrank 156 and to a second crank 158 at 160. Crank 158 isattached to the hinge 162 of the other door 164 shown in outline form.Thus the double doors open and close in unison by remote control. Analternate form of the remote control door operating mechanism is shownin FIG. 10 where the wire 142 is attached at 166 and 168 to twin racks170 and 172. The racks 170 and 172 rotate pinions 174 and 176 which inturn are connected to the door hinges 178 and 180. Doors 182 and 184 areshown in outline form.

In operation, the display model demonstrates visually the operation ofabalanced HVAC system for a supermarket with an air curtain entrancewayand the effect of various changes such as suddenly opening doors on theair currents inside the shopping area. The HVAC system of the displaymodel is first balanced by setting the rheostats for the HVAC fans toprovide a scale flow rate of circulating air within the model. Themakeup air and return air dampers must also be adjusted for the balancedcondition desired. The air curtain fan is set for the scale air curtainflow rate desired. Once a balanced condition is attained then the effectof various architectural defects such as open roof ventilators oropenings in the dividing wall can be demonstrated. The effect of openrear doors or open dividing wall doors can also be shown. The externalfans are utilized to demonstrate that a balanced HVAC system operatingin a properly designed building will prevent undesired air currentswithin the building regardless of external wind conditions. Incomparison, the effect of an open roof ventilator or open rear door willbe readily apparent as external wind conditions are changed.

In summary, the display model demonstrates various architecturalfeatures necessary for maximizing the usefulness of the air curtainentranceway since a store such as a supermarket improperly constructedwill have severe problems with an air curtain entranceway. The displaymodel in operation can demonstrate that a properly designed andoperating system will not have any significant air currents by thefreezer chest or checkout counters regardless of the wind velocity ordirection impinging upon the air curtain entranceway or impinging uponthe air inlet for makeup air to the HVAC system. On the other hand,certain changes such as a supermarket without an air curtain entrancewayand only double doors in the entranceway can be simulated and theresults of the changes on the air circulating, for example, around thecheckout counters and freezer chests, whenever the entrance doors areopen can be demonstrated.

Such models demonstrate important architectural requirements forsuccessful air door installations, such as a completely sealed dividingwall between sales and storage areas in a supermarket, and have provedvaluable not only as sales tools in explaining the feasibility andtechnology underlying successful installations, but actually asdesigning tools in simulating and demonstrating actual air circulationresults under various environmental conditions.

l claim:

1. A portable technical display model comprising a portable table, amodel building mounted on said table, model HVAC ducts located in saidbuilding, a model entranceway incorporated in said building, at leastone interior partition in said building dividing the model into at leasttwo separate model rooms, and a HVAC module connected to said HVAC ductssuch that said HVAC module can be conveniently disconnected andseparately transported.

2. A technical display model according to claim 1 wherein said HVACmodule and said HVAC ducts include mechanical and electrical means tosimulate a working HVAC system in said model building at scalevolumetric air flow rates.

3. A technical display model according to claim 2 wherein said HVACmodule includes at least one fan for circulating HVAC air through saidHVAC ducts and said model building.

4. A technical display model according to claim 3 wherein said HVACmodule includes a second fan incorporated to exhaust air from said modelbuilding and an air supply and damper unit for mixing outside air withreturn air to supply HVAC air to said model building, said unitincluding adjustable dampers to vary the outside air to return airratio.

5. A technical display model according to claim 2 wherein saidmechanical and electrical means include control means to vary the scalevolumetric air flow rates.

6. A technical display model according to claim 1 wherein saidentranceway includes a simulated air curtain,

7. A technical display model according to claim 6 wherein a HVAC ductconnects said air curtain to said HVAC module and air is supplied tosaid duct at scale volumetric fiow rates from an air curtain supply fanlocated in said HVAC module.

8. A technical display model according to claim 7 wherein said aircurtain supply air is recirculated through a HVAC return duct to the aircurtain supply fan.

9. A technical display model according to claim 7 wherein said HVACmodule includes control means to vary the air curtain volumetric flowrate.

10. A technical display model according to claim 1 wherein said HVACducts include upwardly opening fittings to connect with said HVAC moduleand said HVAC module ineludes downwardly opening ducts to connect withsaid fittings such that said HVAC module at least partially rests uponsaid fittings.

11. A technical display model according to claim 10 wherein saidfittings include resilient gaskets to seal said con nections.

12. A technical display model according to claim 2 wherein said HVACmodule includes supply and control means for a fan located externally tosaid building and said HVAC module.

13. A technical display model according to claim 12 wherein a movablefan is connected to said supply and control means and may be directed atsaid building as desired.

14. A technical display model according to claim [2 wherein a fanbracket is removably attached to said table adjacent said entranceway, afan is attached to said bracket, directed at said entranceway andconnected to said supply and control means.

15. A technical display model according to claim 14 wherein said tableincludes a T-slot and said bracket a complementary T-end, said T-endincorporating screw means to tighten said bracket in said T-slot.

Lil

16. A technical display model according to claim 15 wherein said bracketincludes a hinge located between said table and said fan to vary thedirection of said fan at said entranceway, said hinge including screwmeans to tighten said hinge for a desired direction.

17. A technical display model according to claim 1 including apluralitypf wind indicators mounted in said building, at least one ofsaid wind indicators comprising a frame provi ing spaced bearingapertures including low friction bearing material, a rotatable pinjournaled in said bearing aperture holes and a visible sensitive aircurrent indicator mounted on said pin.

18. A technical display model according to claim 1 including at leastone doorway, a door in said doorway, a remote control attached to saiddoor, said remote control including a tube, a push-pull wire in saidtube, an actuating knob attached to one end of said wire, a crankattached to the other end of said wire, the pivot of said crank attachedto the hinge of said door so as to open and close said door uponmovement of said knob.

19. A technical display model according to claim 18 including a seconddoor in said doorway, a second crank attached to said second door, and alink joining said second crank to said first crank forsimultaneousoperation.

20. A technical display model according to claim I including at leastone doorway, a door in said doorway, a remote control attached to saiddoor, said remote control including a tube, a push-pull wire in saidtube, an actuating knob attached to one end of said wire, a rackattached to the other end of said wire and engaging a pinion attached tothe hinge of said door so as to open and close said door upon movementof said knob.

21. A technical display model according to claim 20 wherein a secondpinion is attached to the hinge of a second door in said doorway, asecond rack engages said second pinion and is attached to the end ofsaid wire adjacent said first rack for simultaneous operation.

22. A portable technical display model comprising a portable table, amodel building mounted on said table, model HVAC duets located in saidmodel building, a model entranceway incorporated in said model building,at least one interior partition in said model building dividing themodel into at least two separate model rooms, a HVAC module adjacentsaid model building on said table and connected to said HVAC ducts suchthat said HVAC module can be convenicntly lifted from said table forseparate transportation, a fan in said HVAC module to supply air to saidHVAC ducts, an air curtain in said entranceway, a second fan in saidHVAC module to supply air to said air curtain, an exhaust fan in saidHVAC module, a plurality of wind indicators in said model building, atleast one doorway in said model building, a remotely controlled door insaid doorway, a removable bracket adjacent said entranceway, a fanmounted on said bracket and directed at said entranceway, and controlmeans in said HVAC module to vary the volumetric air flow rate of any ofsaid fans.

23. A technical display model according to claim 22 wherein said HVACducts include upwardly opening fittings and resilient gaskets on saidfittings to seal said connections to said HVAC module by means of theweight of said HVAC module at least partially resting upon saidfittings.

24. A technical display model according to claim 22 wherein said HVACmodule includes an air supply and damper unit to mix return air and makeup air for the supply air to the HVAC ducts.

25. A technical display model according to claim 22 wherein at least oneof said wind indicators comprises a U- shaped nylon block, a hole ineach leg of said nylon block, a rotatable pin joining said holes, and asponge plastic blade mounted on said pin,

26. A technical display model according to claim 1 including a pluralityof wind indicators mounted in said building, at least one of said windindicators comprising a U-shaped nylon block, a hole in each leg of saidblock, a rotatable pin joining said holes and a sponge plastic blademounted on said pin.

1. A portable technical display model comprising a portable table, amodel building mounted on said table, model HVAC ducts located in saidbuilding, a model entranceway incorporated in said building, at leastone interior partition in said building dividing the model into at leasttwo separate model rooms, and a HVAC module connected to said HVAC ductssuch that said HVAC module can be conveniently disconnected andseparately transported.
 2. A technical display model according to claim1 wherein said HVAC module and said HVAC ducts include mechanical andelectrical means to simulate a working HVAC system in said modelbuilding at scale volumetric air flow rates.
 3. A technical displaymodel according to claim 2 wherein said HVAC module includes at leastone fan for circulating HVAC air through said HVAC ducts and said modelbuilding.
 4. A technical display model according to claim 3 wherein saidHVAC module includes a second fan incorporated to exhaust air from saidmodel building and an air supply and damper unit for mixing outside airwith return air to supply HVAC air to said model building, said unitincluding adjustable dampers to vary the outside air to return airratio.
 5. A technical display model according to claim 2 wherein saidmechanical and electrical means include control means to vary the scalevolumetric air flow rates.
 6. A technical display model according toclaim 1 wherein said entranceway includes a simulated air curtain.
 7. Atechnical display model according to claim 6 wherein a HVAC ductconnects said air curtain to said HVAC module and air is supplied tosaid duct at scale volumetric flow rates from an air curtain supply fanlocated in said HVAC module.
 8. A technical display model according toclaim 7 wherein said air curtain supply air is recirculated through aHVAC return duct to the air curtain supply fan.
 9. A technical displaymodel according to claim 7 wherein said HVAC module includes controlmeans to vary the air curtain volumEtric flow rate.
 10. A technicaldisplay model according to claim 1 wherein said HVAC ducts includeupwardly opening fittings to connect with said HVAC module and said HVACmodule includes downwardly opening ducts to connect with said fittingssuch that said HVAC module at least partially rests upon said fittings.11. A technical display model according to claim 10 wherein saidfittings include resilient gaskets to seal said connections.
 12. Atechnical display model according to claim 2 wherein said HVAC moduleincludes supply and control means for a fan located externally to saidbuilding and said HVAC module.
 13. A technical display model accordingto claim 12 wherein a movable fan is connected to said supply andcontrol means and may be directed at said building as desired.
 14. Atechnical display model according to claim 12 wherein a fan bracket isremovably attached to said table adjacent said entranceway, a fan isattached to said bracket, directed at said entranceway and connected tosaid supply and control means.
 15. A technical display model accordingto claim 14 wherein said table includes a T-slot and said bracket acomplementary T-end, said T-end incorporating screw means to tightensaid bracket in said T-slot.
 16. A technical display model according toclaim 15 wherein said bracket includes a hinge located between saidtable and said fan to vary the direction of said fan at saidentranceway, said hinge including screw means to tighten said hinge fora desired direction.
 17. A technical display model according to claim 1including a plurality of wind indicators mounted in said building, atleast one of said wind indicators comprising a frame providing spacedbearing apertures including low friction bearing material, a rotatablepin journaled in said bearing aperture holes and a visible sensitive aircurrent indicator mounted on said pin.
 18. A technical display modelaccording to claim 1 including at least one doorway, a door in saiddoorway, a remote control attached to said door, said remote controlincluding a tube, a push-pull wire in said tube, an actuating knobattached to one end of said wire, a crank attached to the other end ofsaid wire, the pivot of said crank attached to the hinge of said door soas to open and close said door upon movement of said knob.
 19. Atechnical display model according to claim 18 including a second door insaid doorway, a second crank attached to said second door, and a linkjoining said second crank to said first crank for simultaneousoperation.
 20. A technical display model according to claim 1 includingat least one doorway, a door in said doorway, a remote control attachedto said door, said remote control including a tube, a push-pull wire insaid tube, an actuating knob attached to one end of said wire, a rackattached to the other end of said wire and engaging a pinion attached tothe hinge of said door so as to open and close said door upon movementof said knob.
 21. A technical display model according to claim 20wherein a second pinion is attached to the hinge of a second door insaid doorway, a second rack engages said second pinion and is attachedto the end of said wire adjacent said first rack for simultaneousoperation.
 22. A portable technical display model comprising a portabletable, a model building mounted on said table, model HVAC ducts locatedin said model building, a model entranceway incorporated in said modelbuilding, at least one interior partition in said model buildingdividing the model into at least two separate model rooms, a HVAC moduleadjacent said model building on said table and connected to said HVACducts such that said HVAC module can be conveniently lifted from saidtable for separate transportation, a fan in said HVAC module to supplyair to said HVAC ducts, an air curtain in said entranceway, a second fanin said HVAC module to supply air to said air curtain, an exhaust fan insaid HVAC module, a plurality of wind indicators in said model building,at least one doorway in said model building, a remotely controlled doorin said doorway, a removable bracket adjacent said entranceway, a fanmounted on said bracket and directed at said entranceway, and controlmeans in said HVAC module to vary the volumetric air flow rate of any ofsaid fans.
 23. A technical display model according to claim 22 whereinsaid HVAC ducts include upwardly opening fittings and resilient gasketson said fittings to seal said connections to said HVAC module by meansof the weight of said HVAC module at least partially resting upon saidfittings.
 24. A technical display model according to claim 22 whereinsaid HVAC module includes an air supply and damper unit to mix returnair and make up air for the supply air to the HVAC ducts.
 25. Atechnical display model according to claim 22 wherein at least one ofsaid wind indicators comprises a U-shaped nylon block, a hole in eachleg of said nylon block, a rotatable pin joining said holes, and asponge plastic blade mounted on said pin.
 26. A technical display modelaccording to claim 1 including a plurality of wind indicators mounted insaid building, at least one of said wind indicators comprising aU-shaped nylon block, a hole in each leg of said block, a rotatable pinjoining said holes and a sponge plastic blade mounted on said pin.